"Wildest Dream" wrote
especially being it has to be so tight

Do you have a particularly heavy electrical load on your DC system? We tend
to think of the alternator as just a roundy-roundy gadget, but it's actually
capable of transferring a good deal of power from the engine to the wires by
way of that little belt. Combine a heavy load with a somewhat damaged or
misaligned or mis-sized pulley and you could maybe possibly under just the
right circumstances have a recipe for excessive wear.